Patents by Inventor Joachim Kempfert

Joachim Kempfert has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5520482
    Abstract: A soil barrier to prevent the spread of harmful substances in the soil or ground water based on humic substances precipitated in the soil and a process for its creation.
    Type: Grant
    Filed: April 10, 1995
    Date of Patent: May 28, 1996
    Assignee: Rutgerswerke Aktiengesellschaft
    Inventors: Franz D. Oeste, Joachim Kempfert
  • Patent number: 4756818
    Abstract: A method for the production of a carbon fiber precursor from coal tar pitch comprising extracting coal tar pitch at elevated temperatures and pressures with a mixture of a supercritical gas and an entraining agent to obtain a solution free of quinoline-insoluble components, recovering from the solution by lowering the pressure and/or raising the temperature to obtain at least one fraction selected from the group consisting of quinoline-soluble fraction and toluene-soluble fraction, treating the said fraction(s) at to C. under a non-oxidizing atmosphere at atmosphere pressure until 40 to 65% by volume of the product is converted into pitch containing mesophase, extracting the latter pitch with a mixture of supercritical gas and an entraining agent to remove isotropic pitch and recovering isotropic pitch with a mesophase content of at least 75% by volume, a pyridine-insoluble matter content of 20 to 50% by weight, a mean molecular weight of 900 to 1200 and a melting point of
    Type: Grant
    Filed: February 24, 1987
    Date of Patent: July 12, 1988
    Assignee: Rutgerswerke Aktiengesellschaft
    Inventors: Siegfried Peter, Herbert Beneke, Franz Oeste, Wolfgang Fexer, Wolfgang Jaumann, Manfred Meinbreckse, Joachim Kempfert